Previously, as high-luminosity light-emitting diodes (abbreviation: LEDs) for emission of red or infrared light, compound semiconductor light-emitting diodes have been known which are provided, for example, with a light-emitting layer consisting of aluminum gallium arsenide (composition formula: AlXGa1-XAs; 0≦X≦1) or a light-emitting layer consisting of indium gallium arsenide (composition formula: InXGa1-XAs; 0≦X≦1). On the other hand, as high-luminosity light-emitting diodes for emission of visible light of red, orange, yellow, or yellow-green, compound semiconductor light-emitting diodes are known that are provided, for example, with a light-emitting layer consisting of aluminum gallium indium phosphide (composition formula: (AlXGa1-X)YIn1-YP; 0≦X≦1, 0<Y≦1).
With respect to such compound semiconductor light-emitting diodes, for example, there is a manufacturing method, wherein a compound semiconductor layer provided with a light-emitting layer as described above is affixed to a substrate of Si or the like via a high-reflectance metal layer (reflecting layer), after which a growth substrate used for growth (e.g., GaAs substrate) is removed. In this instance, Au, Al, Ag or the like may be cited as the metal used in the reflecting layer.
However, such a reflecting layer using high-reflectance metal cannot be ohmically bonded to an aluminum gallium indium phosphide compound semiconductor layer.
Moreover, when the compound semiconductor layer and the reflecting layer come into direct contact, an alloy layer is formed by the reaction of the reflecting layer and the compound semiconductor layer, which may cause the problem that reflectance is degraded.
To solve this problem, there is a method which interposes transparent film between the compound semiconductor layer and the reflecting layer, and which disposes ohmic contact electrodes so as to penetrate this transparent film, and contact the compound semiconductor layer and the reflecting layer (see Patent Documents 1, 2).